1. Field of Invention
The invention involves a needle sheath complex and related process for performing biopsies, decompressions and similar operations at most locations within human and animal bodies without opening the body or doing substantial damage to the structures of the body. The location of the area and structures within the body to be decompressed, sampled or treated in various ways is located by insertion of a relatively small needle which enables location and verification of location. Before removal the needle, is used as a guide over which a large sheath is slid into place stretching the opening along the needle to drain the area or take the sample etc. The subject device and process have virtually unlimited applications for locating and then gaining access to virtually any part of the human or veterinary anatomy including for example the brain, ventricular system, cystic masses, liver, biliary tree, and kidneys.
2. Description of the Prior Art
The use of a small needle (22 to 23 gauge) to locate tumors, or normal structure such as a kidney or an artery has become routine in the last several years because this gauge needle can pass through most of the human anatomy without doing significant damage. However, a needle this size is to small to permit adequate drainage for therapeutic purposes (decompression of the biliary tree or urinary tract, etc.) and it is too small to extract samples of infected material or suspect structure for diagnostic purposes. The small needle captures only cells which at times is not adequate for a definitive diagnosis. Accordingly, a larger needle (15 to 18 gauge) is required to do these jobs. The larger size can be extremely dangerous if multiple passes are required and where arteries or other sensitive structures may be punctured sufficiently to cause internal bleeding or malfunction. A second entry with a larger needle which may again require multiple attempts presents a risk that the present invention can minimize while offering a multitude of advantages and capabilities previously unavailable.